Syria crisis: Obama could call off any US strikes if Assad hands over chemical weapons

President Barack Obama said he was prepared to call off US strikes on Syria last night if the Assad regime agreed to hand over its chemical weapons arsenal – even as he expressed scepticism that Damascus would take such an offer seriously.

Mr Obama said the US would give serious examination to a Russian proposal to put Syria's chemical stockpiles "under international control" a move which – if it happened – he said would represent a "significant breakthrough" that would avert the prospect of American strikes.

The rapid developments in Washington open the door to a diplomatic solution to the international crisis over how best to respond to the August 21 chemical weapons attacks that the US says were carried out by the Assad regime, leaving more than 1,400 dead.

Minutes after Mr Obama spoke the Senate seized on the Russian proposal as an opportunity to delay a planned vote on attacking Syria and avoid the possibility of a humiliating defeat for the White House which struggled to persuade Congress of its case for punitive military action.

Mr Obama's decision to explore the Russian proposal came hours after John Kerry, the US secretary of state, made an off-the-cuff remark at a London press conference, saying hypothetically America would hold off on strikes if Bashar al-Assad surrendered his chemical weapons.

The comment was picked up by Sergei Lavrov, the Russian foreign minister, who urged Syria to agree to the handover and "subsequent destruction" of their arms. Syria responded by "welcoming" – but not explicitly accepting – Russia's idea.

As the unexpected initiative gained traction in capitals across the world, Mr Obama was asked by ABC News if he would call off strikes if the Assad regime did hand over its chemical arsenal. "Absolutely," he replied, "If in fact that happens." Mr Obama said that Secretary of State John Kerry would now explore with Russia how serious the offer was, telling Fox News that he expected to gain a "fairly rapid" sense – at least within the two week time frame of the proposed Congressional vote – of whether Assad was prepared to give up the weapons.

He was careful to inject a note of caution, saying that any proposal from Russia and Syria could not be used as "a stalling or delaying tactic" by Damascus.

Neither side offered details of how the plan could work or how Mr Assad's arsenal could be safely transported through the chaos of Syria's civil war.

Mr Obama said that while the US explored the suggestion further he would keep up American pressure on Syria, saying it was "unlikely that we would have arrived at the point where there are even public statements like that without a credible military threat".

While the unexpected Russian initiative offers a potential reprieve for Mr Assad it also offers a possible escape route for Mr Obama who has struggled to rally the votes needed in Congress to avoid defeat.

Despite a week-long all-out public offensive to convince members of Congress to back the strikes, the White House has so far failed to secure the votes it needs.

"I wouldn't say I'm confident," Mr Obama said when asked if he could muster the support to get his proposal for military action through the Senate and the House of Representatives.

Soon after the president's interviews aired, Harry Reid, the Democrat Senate leader, announced he was delaying Wednesday's planned vote, which would have been a critical test of Mr Obama's support in Congress.

Mr Reid said publicly the delay was to give the White House more time to present the case for war "to the Senate and the American people" but aides privately acknowledged he had seized on the Russian proposal.

Senator John McCain, the leading Republican proponent of strikes, said that the Russian plan should make Congress "more willing" to vote for action in order to keep pressure on the Assad regime.

Mr Obama will still go ahead with a major speech on Syria from the White House on Tuesday but his aides will alter it to reflect the slowing down of America's march to war.

The president said he had not decided whether he would follow David Cameron's example and abandon plans for strikes if Congress voted against it. The White House has always insisted that he has the legal authority to order military action without Congressional approval.

Mr Obama also dismissed veiled threats by Bashar al-Assad that Syria would retaliate against an American attack, saying: "He doesn't have a credible means to threaten the United States."

The president said that while Iran and Hizbollah, the Lebanese militia fighting for Mr Assad, could try terrorist attacks "the kinds of threats they could pose against us are typical of the kind of threats that we're dealing with around the world".